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Re: Confusion over classification of dinosaurs



On 30 Nov 1999, Berislav Krzic wrote:

>        1. World famous palaeontologist Robert T. Bakker recently discovered a
> new 'miniature' version of Tyrannosaurus
>        Rex and named it Nannotyrannus, meaning 'little tyrant'. How does he
> and other palaeontologists know this is a
>        completely new genus and species and NOT just a juvenile or
> 'half-grown' T. Rex?

In fact, it is now thought to be a juvenile _Tyrannosaurus_ (probably
_T. rex_).
 
>        2. Is the English dinosaur Baryonix Walkerii, with a head similar to
> the giant Suchomimus Tenerensis, just a
>        Spinosaurid without a sail, or is it still classified as a
> Baryonichid?

_Suchomimus_ and _Baryonyx_ are baryonychine spinosaurids.
 
>        3. Is Yangchuanosaurus the Chinese eqivalent of the North American
> Allosaurus or Ceratosaurus, I have conflicting
>        information on this?

_Yangchuanosaurus_ is an allosauroid.
 
>        4. Were there any known sauropods that survived right up until the end
> of the cretaceous?

Yes. _Alamosaurus_, for one. Sauropods were more common in Gondwana than
in Laurasia during the Cretaceous, and I don't think there are any
Gondwanan late Maastrichtian deposits (correct me if I'm wrong).
 
>        5. In the last century, Edward Drinker Cope discovered a meat eating
> dinosaur which he named 'Laelaps'. It is now
>        known as Dryptosaurus, the 'wounding reptile'. It has two fingers on
> each hand and looks for all the world like a
>        member of the Tyrannosaurid family. So why isn't it classified as
> such?

It has three fingers and is a basal coelurosaur.
 
>        6. Why do there seem to have been no large ceratopsians on any other
> continent besides North America?

The continents were very broken up by the time that ceratopsids evolved.
They did not have a chance to spread to other continents. _Turanoceratops_
is a large ceratopsian (not a ceratopsid, though -- probably) from Asia.
 
This info and more at: http://dinosaur.umbc.edu/

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